1. Field Of The Invention
The present invention deals with the field of refrigerated display cases and more particularly with the field of open front refrigerated display cases wherein one or more air curtains are defined extending vertically across the open front area defined therein. Such open front refrigerated display cases retain refrigerated air therein and yet facilitate easy removal of product displayed therein by a shopper.
The open front refrigerated display case of the present invention deals more particularly with those cases having an ambient air defrost means which have been found to be highly energy efficient and aid in the defrosting of the refrigerating coil thereof without requiring external heaters or use of hot refrigerant gases. Such ambient air defrost systems have proved unsatisfactory because of the recirculation of cool air during ambient defrost rather than allowing dry room temperature ambient air to constantly be passed over the refrigeration coil for cooling. The present invention provides a means for overcoming the recirculation of cooled air and provides a continuous supply of ambient air to the ambient air defrost device during ambient air defrost operation.
2. Description Of The Prior Art
Open front refrigerated display cases and particularly those including ambient air defrost systems have included many different patented configurations such as U.S. Pat. No. 2,463,614 patented Mar. 8, 1949 to H. Hardin on an Open-Top Display Refrigerator; U.S. Pat. No. 2,495,554 patented Jan. 24, 1950 to G. Spangler on an Open top Refrigerated Display Case; U.S. Pat. No. 2,594,066 patented Apr. 22, 1952 to R. Pabst on a Two-Decker Dairy Self-Service Refrigerator; U.S. Pat. No. 2,630,684 patented Mar. 10, 1953 to M. Strang on a Refrigerated Multiple Shelf Display Case; U.S. Pat. No. 2,952,992 patented Sept. 20, 1960 to D. Voorhies on a Refrigerated Shelf; U.S. Pat. No. 2,993,349 patented July 25, 1961 to W. Detwiler on a Refrigerated Display Case; U.S. Pat. No. 3,094,851 patented June 25, 1963 to S. Beckwith on a Refrigeration Cabinet And Defrost; U.S. Pat. No. 3,103,796 patented Sept. 17, 1963 to E. Dickson et al on a Refrigeration System; U.S. Pat. No. 3,186,185 patented June 1, 1965 to G. Bently et al on a Refrigerated Display Unit; U.S. Pat. No. 3,229,475 patented Jan. 18, 1966 to J. Balk et al on a Refrigerated Display Case; U.S. Pat. No. 3,287,929 patented Nov. 29, 1966 to S. Beckwith on a Refrigerated Cabinet With Improved Nozzle Construction; U.S. Pat. No. 3,304,736 patented Feb. 21, 1967 to J. Brennan et al on a Refrigerated Display Case; U.S. Pat. No. 3,304,740 patented Feb. 21, 1967 to E. Dickson et al on an Open Front Display Case; U.S. Pat. No. 3,319,557 patented May 16, 1967 to A. Perez on a Self-Adjusting Air Deflector; U.S. Pat. No. 3,324,676 patented June 13, 1967 to L. Gerweck on a Refrigerated Display Case; U.S. Pat. No. 3,365,908 patented Jan. 30, 1968 to M. MacMaster on a Display Case; U.S. Pat. No. 3,369,375 patented Feb. 20, 1968 to L. Gerweck et al on a Refrigerated Display Case; U.S. Pat. No. 3,403,525 patented Oct. 1, 1968 to S. Beckwith et al on a Defrost System For Air Curtain Type Refrigerated Display Case; U.S. Pat. No. 3,465,536 patented Sept. 9, 1969 to R. Vogel et al on a Removable Cover For Access Opening Of Refrigerated Cabinet; U.S. Pat. No. 3,499,295 patented Mar. 10, 1970 to J. Brennan on a Refrigeration System; U.S. Pat. No. 3,501,925 patented Mar. 24, 1970 to J. Brennan et al on Refrigerated Equipment; U.S. Pat. No. 3,517,526 patented June 30, 1970 to M. MacMaster et al on Refrigerated Equipment; U.S. Pat. No. 3,528,258 patented Sept. 15, 1970 to J. Brennan on a Refrigerated Display Case; U.S. Pat. No. 3,531,945 patented Oct. 6, 1970 to J. Brennan on Constant Temperature Refrigerated Equipment; U.S. Pat. No. 3,648,482 patented Mar. 14, 1972 to S. Beckwith et al on a Method And Apparatus For Producing Refrigerating Constructions; U.S. Pat. No. 3,675,440 patented July 11, 1972 to F. Ibrahim on a Refrigerated Display Case; U.S. Pat. No. 3,751,653 patented Aug. 7, 1973 to J. Henry on a Refrigerated Display Case; U.S. Pat. No. 3,756,038 patented Sept. 4, 1973 to M. MacMaster et al on Refrigerated Display Equipment; U.S. Pat. No. 3,827,254 patented Aug. 6, 1974 to M. MacMaster on a Refrigerated Display Case; U.S. Pat. No. 3,850,003 patented Nov. 26, 1974 to S. Beckwith et al on an Air Defrost Air Curtain Display Case; U.S. Pat. No. 3,937,033 patented Feb. 10, 1976 to S. Beckwith et al on an Air Defrost Display Case; U.S. Pat. No. 4,077,228 patented Mar. 7, 1978 to N. Schumacher et al on a Refrigerated Display Case; U.S. Pat. No. 4,144,720 patented Mar. 20, 1979 to E. Subera et al on an Air Defrost System Using Secondary Air Band Components; U.S. Pat. No. 4,302,946 patented Dec. 1, 1981 to F. Ibrahim on a Refrigeration System Using Air Defrost; U.S. Pat. No. 4,319,463 patented Mar. 16, 1982 to H. Ljung on a Refrigerated Display Chest; U.S. Pat. No. 4,320,631 patented Mar. 23, 1982 to J. Vana on an Air Defrost For Low-Bed Refrigerated Display Cases, Utilizing Sill-Mounted Auxiliary Fan; U.S. Pat. No. 4,375,155 patented Mar. 1, 1983 to R. Rosanio et al on a Reach-In Refrigerated Display Case With Ambient Air Defrost; U.S. Pat. No. 4,514,988 patented May 7, 1985 to F. Ibrahim on a Refrigerated Display Case Having Ambient Air Defrost; U.S. Pat. No. 4,592,209 patented June 3, 1986 to G. Casanova et al on a Display Counter For Food Products, Refrigerated By Forced Ventilation; U.S. Pat. No. 4,750,335 patented June 14, 1988 to G. Wallace et al on an Anti-Condensation Means For Glass Front Display Cases; and U.S. Pat. No. 4,760,708 patented Aug. 2, 1988 to M. Karashima on a Refrigerated Showcase.